Atrial fibrillation (AF) is the most common arrhythmic
complication in the postoperative period, occurring in about a third of
patients undergoing coronary artery bypass graft surgery (CABG) [1, 2].
It is
typically seen between the second and fourth postoperative days [3] and
is associated with a significantly increased risk of postoperative
stroke [1] and in-hospital mortality [4]. Treatment strategies are
targeted at rate or rhythm control and anticoagulation for prevention
of thromboembolic complications. However, treatment is often difficult
and associated with significant morbidity, making this a classic
situation where prevention is better than cure.

Pharmacological interventions have been the mainstay of preventive
therapy. Beta blockers have been shown to be the most effective
preventive therapy and it is recommended now to continue or initiate
beta blocker therapy for all patients in the perioperative period [5].
Amiodarone is also an effective drug, but the intravenous preparation
is associated with a risk of hypotension [6] and oral therapy has to be
begun several days before surgery [7]. Sotalol [8], magnesium [9],
statins [10,11], N-3 polyunsaturated fatty acids [12] and
anti-inflammatory agents [13] are other pharmacologic measures that
have been shown to be useful in various trials.

Atrial pacing is an attractive non-pharmacological intervention for the
prevention of atrial fibrillation. Pacing in the postoperative period
is easy to implement since it is only required for a short period and
can therefore be performed using epicardial temporary pacing wires
placed by the surgeon. The mechanisms by which atrial pacing is
postulated to reduce the incidence of atrial fibrillation include
reduction of bradycardia induced dispersion of atrial repolarization
and overdrive suppression of atrial premature beats. Dual site atrial
or biatrial pacing may result in additional benefit by promoting more
synchronised atrial depolarization which results in reduced dispersion
of atrial refractoriness and by altered atrial activation patterns that
may prevent the development of intra-atrial reentry [14]. Prophylactic
pacing has been shown in a number of trials to reduce the incidence of
AF after CABG [15]. In a small randomized trial, biatrial pacing was
shown to be superior to single site atrial pacing [16].

In this issue of the journal, Chavan et al [17] report on their results
with the use of Bachmann bundle pacing as an alternative approach to
pacing in the postoperative period. Significantly reduced paced P wave
duration confirms the hypothesis that pacing at this site results in
more synchronised atrial activation with lesser total atrial activation
time. This, in turn, led to a significantly reduced incidence of AF
compared to patients who received conventional right atrial pacing or
those with no pacing. Although the results need to be interpreted with
caution given the small number of study patients and a previous trial
showing no benefit with atrial septal pacing [18], the results suggest
promise for Bachmann bundle pacing to emerge as a simple preventive
measure that may be at least as effective as pharmacologic therapy
without the associated adverse effects.